## Lucas Duda’s .422 OBP and Anthony Recker’s Weird Slash Line April 28, 2015

Posted by tomflesher in Baseball.
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Mets first baseman Lucas Duda has an alarming .422 OBP and .507 SLG this year, including 2 HBP and a 15/11 KBB ratio. That’s quite a bit above Lucas’ previous year OBPs – since 2011, Lucas had gotten on base .370, .329, .352, and .349 times per plate appearance, in order. That’s centered almost exactly around .350.

In 20 games, Lucas has made 83 plate appearances. What are the chances that Lucas is hitting about where he did previously, but had a hot streak of facing pitchers who gave him what he needed?

The standard error for an n-trial sample of a binary variable with probability p is $\sqrt{\frac{p(1-p)}{n}}$. If we assume Lucas’ ‘true’ OBP is .350, then the standard error of this 83-trial sample would be $\sqrt{\frac{.35(.65)}{83}} = \sqrt{\frac{.2275}{83}} = \sqrt{.00274} = .052$. That means about 66% of Lucas’s 83-plate-appearance streaks should be within one standard error, and about 95% should be within two. Due to the small sample size, it’s hard to be 95% sure that Lucas’ performance is due to actual improvement, but the upper bound of the 66% confidence window would be about .402. Lucas is outperforming that by about 20 basis points.

Meanwhile, backup catcher, relief pitcher, and third baseman Anthony Recker is on the other side – he’s made 11 plate appearances, walking four times, striking out 4, and not yet hitting the ball. Though none of those walks are intentional, that leaves Recker with a .000/.364/.000 line – quite far off from his lifetime .194/.268/.364 BA/OBP/SLG line. No wonder Kevin Plawecki is starting. Recker’s hitting probably isn’t that much different from last year’s .200 average – we can be 95% sure he’s not likely to hit much above .300 without some extra batting practice, but otherwise it’s not unusual for a .200 hitter to have a streak of 7 at-bats with no hits, especially since he’s working walks, too.